I tried the figures for a 50 year mortgage, asking the question "how much equity will I have built up after 20 years?"

50 year mortgage on a 400,000 home with 20% down, 6.276% interest rate. No property taxes, homeowners, etc.

At the 20 year mark, you will have paid off $39,843 while paying $383,491 of interest to the bank.

Now you have locked in your base housing cost (without insurance, property taxes, etc) at $1,751/month for those 20 years, which is better than dealing with rent increases.

If your house value increases faster than that mortgage interest rate, yeah you'll end up net ahead if you sold at the 20 year mark. But looking at Knoxville's historic housing prices, no, our market has not increased 6% a year for the last 20 - it's been lower than that. Maybe we are normalizing more towards that after a really low-return decade (2008-2017 where we had years of negative value and no years above 5% increase in value).

The real winner is that bank, which made a reliable interest payment from you for those 20 years. You're really renting from a bank instead of a landlord if you're on a 50 year mortgage.

I've said the secret to my success is the 15 yr loan. Because it's a forced savings account.
Since I liked to buy old houses it was good to have equity to tap into for repairs. But even a new house will need updates starting at 10-15 yrs.
The first mortgage I got from a credit union had a 12 yr amortization. Why? I made a chart one time and figured out principal payments didn't really accelerate until one was 12 years prior to payoff.

Too bad 20 yr mortgages aren't readily available. That seems like a good compromise to keep payments low. 50 yrs is just ridiculous.

Buying a home used to be a milestone of early adulthood. Now the median first-time buyer is 40.

Homeownership used to start in your 20s. Now it starts closer to retirement. What happened?